// Continue from here to calculate the forecast#"Added Custom4" = Table.AddColumn(SortedTable, "Forecast", each    let        // Find values for 7 days prior and multiply by 0.4        ActualTotal7 = List.First(List.Select(SortedTable[Actual Total], each [Date] = Date.AddDays([Date],-7))) * 0.4,        // Find values for 14 days prior and multiply by 0.3        ActualTotal14 = List.First(List.Select(SortedTable[Actual Total.7], each [Date] = Date.AddDays([Date],-14))) * 0.3,        // Find values for 21 days prior and multiply by 0.2        ActualTotal21 = List.First(List.Select(SortedTable[Actual Total.1], each [Date] = Date.AddDays([Date],-21))) * 0.2,        // Find values for 28 days prior and multiply by 0.1        ActualTotal28 = List.First(List.Select(SortedTable[Actual Total.2], each [Date] = Date.AddDays([Date],-28))) * 0.1,        // Sum the results to get the final forecast        Forecast = ActualTotal7 + ActualTotal14 + ActualTotal21 + ActualTotal28    in        Forecast),to this:let

// To continue from here and calculate the forecast, add a new column called "Forecast" to the SortedTable. Use the "each" keyword to define a function that performs the following steps:

1. Find the value for 7 days prior by selecting the first value from the SortedTable[Actual Total] column where the [Date] is equal to Date.AddDays([Date], -7). Multiply this value by 0.4 and assign it to the variable ActualTotal7.

2. Find the value for 14 days prior by selecting the first value from the SortedTable[Actual Total.7] column where the [Date] is equal to Date.AddDays([Date], -14). Multiply this value by 0.3 and assign it to the variable ActualTotal14.

3. Find the value for 21 days prior by selecting the first value from the SortedTable[Actual Total.1] column where the [Date] is equal to Date.AddDays([Date], -21). Multiply this value by 0.2 and assign it to the variable ActualTotal21.

4. Find the value for 28 days prior by selecting the first value from the SortedTable[Actual Total.2] column where the [Date] is equal to Date.AddDays([Date], -28). Multiply this value by 0.1 and assign it to the variable ActualTotal28.

5. Sum the values of ActualTotal7, ActualTotal14, ActualTotal21, and ActualTotal28 to get the final forecast. Assign this sum to the variable Forecast.

Finally, return the value of Forecast as the result of the function.

The updated code should look like this:

"Added Custom4" = Table.AddColumn(SortedTable, "Forecast", each let ActualTotal7 = List.First(List.Select(SortedTable[Actual Total], each [Date] = Date.AddDays([Date],-7))) * 0.4, ActualTotal14 = List.First(List.Select(SortedTable[Actual Total.7], each [Date] = Date.AddDays([Date],-14))) * 0.3, ActualTotal21 = List.First(List.Select(SortedTable[Actual Total.1], each [Date] = Date.AddDays([Date],-21))) * 0.2, ActualTotal28 = List.First(List.Select(SortedTable[Actual Total.2], each [Date] = Date.AddDays([Date],-28))) * 0.1, Forecast = ActualTotal7 + ActualTotal14 + ActualTotal21 + ActualTotal28 in Forecast)